Abstract: There have many disadvantages about the expression of light and shadow in the existing 3D map. For example, it lacks variation of representation technique, it is short of adjustment function and has only a limited cognitive effect. To improve this situation, this paper discusses the change rules of the color of light and shadow along with latitude, longitude and time in terms of Chromatology. The author takes the people's spatial cognition custom fully into account to build a simple and feasible model of light and shadow in 3D map. This model can simulate the spatial-temporal variation processes and rules conveniently and realistically. It can also provide a basis for using the existing 3D modeling software or developing the visualization software of 3D map by component technology, and strengthen the visual effect of 3D map.